Treffer: High-Fidelity SiMOS Spin Qubits: From Academic to Industrial Devices

The ground-breaking impact of quantum computing across the natural sciences - ranging from physics and chemistry to medicine and climate science - paired with its political, societal, and commercial relevance in areas such as cybersecurity, pharmaceutical design, machine learning, and financial modelling (to name just a few), makes the development of a large-scale quantum computer a matter of national security, often referred to as the "quantum race"'. Utility-scale, fault-tolerant quantum computing processors require quantum operations across the entire chip or network of systems with error rates below the threshold for quantum error correction to harness their full capabilities. Among the many types of qubits currently being investigated for a future quantum computer, silicon spin qubits are uniquely positioned to enable quantum computing with millions of qubits on a single chip. In this work focuses on silicon metal-oxide-semiconductor (SiMOS) quantum dots, which can leverage the mass-fabrication and miniaturisation capabilities of the silicon industry. We discuss advances in silicon-based quantum computing through a series of manuscripts that collectively address high-fidelity operations in academic prototype and 300 mm wafer devices, their scalability and reproducibility via industry-compatible manufacturing, and thermal robustness of electron spin qubits. First, we show high-fidelity violation of Bell’s inequality with Bell signal close to the theoretical limit of 2√2 using academic cleanroom gate-defined quantum dot prototype device, demonstrating both the quantum coherence and control precision necessary for scalable entanglement operations in quantum computing. Notably, these experiments are also conducted at elevated temperatures, highlighting high-temperature operation as another key advantage of this qubit implementation. Second, transitioning to industry compatibility and scalability, we report on multiple silicon spin qubit unit cells fabricated on a 300 mm wafer. Despite the shift from ...